I can't tell you exactly what is missing but if you enjoy movies with suspense, action and can take a little horror then I would recommend watching. I will say that I have a bit of I bias because kitty in Nanno is one of my favorite suspense/ thriller shows, and I've gone through a few of mark Thai dramas where he plays as the main love interest.

What I liked
·It has nice cinema photography.
·The character development is shown well
·The acting is really good ( I love kitty and mark so much they never disappoint)

What I disliked:
·The CGI could have been better